Velocity stacks were developed/popularized for racing. The early Hilborn fuel injectors used velocity stacks. In racing, the engines are running at wide open throttle (WOT) most of the time and this is where the velocity stack is tuned. They are trying to develop a pressure wave at the WOT rpm to create a supercharging effect.
The stack also improves the way the air flows into the engine. The width, length, and radius of the inlet of the velocity stack play a role in the performance of it.
The velocity stack has similarities to a pipe organ and a trumpet. If you blow air through either instrument, you get a note of a particular frequency out because the air resonates. You are doing the same thing with your car engine...... the rpm's at WOT are the "note" you are trying to tune the engine. In your case, if you change the length of the dipping sauce container, it will change the note to which you are attempting to tune the engine. I don't think velocity stacks give you a big performance gain ........ the numbers seem to be less than 5%. So, you might get an extra 1 hp out of the Honda 600.
I have seen velocity stacks used with fuel injection and carb systems which have a constant geometry where the air flows into the induction system. The Honda 600 has the variable venturi carb which moves a piston up and down based on the pressure difference across it and this changes the geometry of this area. It seems like the pressure wave you are trying to develop with the velocity stack is going to mess up carb at the higher rpms. I am thinking you will have something which works well at the one rpm it gets tuned at (e.g. 4000 rpm) but will give poorer performance at other higher rpms (e.g. 3000 and 5000).
Rather than playing with velocity stacks, I think you will see better results if you spent your time on exhaust tuning. Someone else in an earlier msg pointed out that your side pipes may be lessening your exhaust back pressure. What you are attempting to do with the velocity stack on the inlet, you can also do on the exhaust side. You can tune the engine for better performance across an rpm range.
I'll be interested in seeing what you are able to achieve.
good luck,
Dale
> Need to go faster ! Need more power ! The Honda
> z600 sure makes an nice intake howl now, however, I'm not sure how much of a > horsepower improvement it made. I did notice it actually richened up the > mixture under full throttle a couple of decimal points. I'm going to add in > more timing to see how she responds. Micro Muscle Madness > continues.
> https://www.youtube.com/watch?v=3FykmszCUck
> Mark
> Portland
> Or.
> www.mphspecialties.com